# Add and Subtract Integers Notes Powerpoint

```Integers
Two Negative Numbers
Two Positive Numbers
Ex.) -4 + -3
Ex.) 2 + 9
•
been doing this since 2nd Grade.
•
Just add the numbers, and keep
the negative sign.
-4 + -3 = -7
2 + 9 = 11
• Illustration
• Illustration
+
+
-
-
-
+
+
+
+
+
+
-
-
-
+
+
+
-
One number is Positive,
One number is negative
Ex.) 6 + -5
•
Subtract the Absolute Value of the
Numbers, and take the sign of the
larger Absolute Value
6 + -5 = 1
•
Abs. Value of 6 = 6
•
Abs. Value of -5 = 5
•
6-5=1
•
6 is larger than 5, so the answer
is positive, because the 6 is
positive
•
+
-
Remember:
+
-
A + plus a – cancel
each other out.
+
-
+
-
+
-
Illustration
+ + - =0
+
More Examples
Ex.) -5 + 3
(Different Signs…)
Ex.) -3 + -7
(Same Signs…)
Visual
Visual
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-
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+
-
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+
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+
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• Opposite Pairs
+
-
• A + and a – cancel each other out.
• Have \$/Owe \$
• Think of Positive Numbers as having \$, and think of Negative Numbers as
owing someone \$.
www.wpclipart.com/money/money_bag_green.png
• Number Line Walk
• Put Sammie on the number line above the 1st #, then “walk” Sammie the
number of space of the 2nd #. If the 2nd # is positive, walk to the RIGHT, if it
is negative, walk to the LEFT.
•
dhardhar.files.wordpress.com/2009/08/cartoon-...
Subtracting
• You have been
subtracting “Positive
Ex.) 12 - 8 =
Ex.) 9 – 7 =
Ex.) 53 – 22 =
• KFC—Keep, Flip, Change
Keep—the sign of the 1st Number
Flip—the operation + becomes –
Change—the sign of the 2nd Number
So,…
• BUT…from now on…we
are going to change
KFC
Ex.) 12 – 8
becomes 12 + -8
Subtracting—use KFC
Ex.) 7 – 11=
(KFC…7 + -11=) now use an
Ex.) -7 – 12=
Ex.) 8 – 16=
Ex.) -4 – 1=
Ex.) 3 – 12=
Ex.) 5 – -2=
Ex.) -8 – -6=
Multiplying &amp; Dividing
• The Triangle Trick
Ex.) 9 &times; -8 =
+
Ex.) -28 &divide; 7=
-
1. &times; or &divide; the
numbers.
2. Cover up the Signs of
the numbers.
3. The sign left over, is the